1. Field of the Invention
The present invention relates to a method of cleaning contaminated water by charging electrical energy to the water in lakes, rivers, marshes or waste water reservoirs in factory sites, and an apparatus therefor.
The term "cleaning" in this specification is defined as decrease of oxidation-reduction potential (ORP), turbidity, smell, chemical oxygen demand (COD), phosphate concentration as well as increase in amount of dissolved oxygen in the water.
2. Related Art
Nowadays water in lakes, rivers and others has been contaminated with waste from general homes, factories, golf links and other sources to cause a serious public pollution.
Hitherto, an aeration treatment has been well known for cleaning the water in lakes and others, which has been widely employed for treating sewage. The aeration treatment is effected by blowing fresh air into contaminated water and/or sucking-up contaminated water in depth layer to expose the same to atmospheric air.
With recourse to such aeration treatment, however, an economically inhibited huge installation would be required for cleaning of water in lakes or marshes, and such mechanical water cleaning would be limited to relatively small areas, and the treatment of whole water in lakes or marshes would be almost impossible. The degree of contamination is determined in terms of turbidity, offensive smell, content of dissolved oxygen, chemical oxygen demand, phosphate concentration and other factors. The mechanical water cleaning can improve the quality of water in terms of selected items only.
In contrast to such mechanical water cleaning, an electrical water treatment is found to be useful in treating a relatively small amount of water, for instance for the purpose of improving quality of drinking water such as city water, well water and the like, but conventional electrical water cleaning methods and apparatuses are practically useless in treating a lot of badly contaminated water in lakes and others. Therefore, there has been an ever increasing demand on practical water cleaning method and apparatus to be applied to contaminated water in lakes and others for improving human life environment.